Parametric equations for the variables of a steady-state model of a multi-effect desalination plant

Abstract

2013) Parametric equations for the variables of a steady-state model of a multi-effect desalination plant, Desalination and WaterIn this work a steady-state model is developed of an MED plant. Its development and validation have been carried out by experimental data obtained from an MED pilot plant located at the Plataforma Solar de Almería (PSA), in the southeast of Spain. It is a vertical arrangement forward-feed MED plant with preheaters, which uses hot water as the thermal energy source. In order to run the model, a series of parametric equations have been determined for the following variables: the overall heat transfer coefficient for the first effect (U h ), the overall heat transfer coefficient for the preheaters (U p (i)), the vapor temperature inside the first effect (T v (1)), and the cooling seawater outlet temperature (T cwout ). They have been obtained from a three-level factorial experimental design (3 k ), performing a total of 81 experiments (3 4 ). The results obtained showed a good fit to the estimated models for the response variables.

Dynamic modeling and simulation of a solar-assisted multi-effect distillation plant

“…The cooling seawater is spilt into the big pool and part of the heat released by the condenser could increase its temperature during an experiment. To avoid that, a dry cooler is switched on, however sometimes it is insufficient [11]. Therefore, it is difficult to obtain a long-steady state in all its variables even though the MED plant has control mechanisms at its inputs.…”

“…The current design specifications of the MED plant are shown in Table 1 [11]. All the tube bundles are made of 90-10 Cu-Ni with a 14 mm of outside diameter.…”

“…This system expels the gases at the beginning of the experiment, being water vapor the only gas inside the effects. The hydro-ejectors are within a closed circuit with a tank and an electric pump that drives seawater through the ejectors at a pressure of 3 bar [11].…”

“…Some of the most recent contributions in this area have been done by Kouhikamali who studied the influence of different configurations of feed water preheating [6], Joo and Kwak who increased the mechanical efficiency and economic profit of a MED system [7] or Palenzuela et al who evaluated different cooling technologies of concentrating solar power plants and their combination with desalination processes (RO and MED) [8]. The contributions made by El-Nashar [9,10] and Palenzuela et al [11] deserve special attention because they validated their respective models with experimental data.…”

Concentrating Solar Power and Desalination Plants

“…The authors of this book carried out an evaluation of wet (evaporative water and once-through) and dry cooling technologies for different CSP + D configurations (with MED and RO desalination plants) in the Mediterranean area and the Arabian Gulf (Palenzuela et al 2013(Palenzuela et al , 2015. It was found that the use of evaporative water cooling was the most economical in terms of electricity production.…”